Thread winding device

ABSTRACT

In apparatus for the winding of continuous thread, the tension of the thread is maintained constant during winding by an arrangement adapted to regulate the contact force between the roller and the reel, such regulation taking place as a function of the diameter of the reel while it is being wound.

1: ited States Patent [191 I unaioli et a1.

[ THREAD WINDING DEVICE [75] Inventors: Ettore Funaioli, Bologna; Piercarlo Landini, Busto Arsizio; Giulio Marella, Palazzolo Sull Oglio, all of Italy [73] Assignee: SocietaItaliana Resine S.p.A., Milan, Italy [22] Filed: July 1, 1971 21 Appl. N0.: 158,825

[30] Foreign Application Priority Data July 1, 1970 Italy 26847 A/70 [52] US. Cl. 242/18 DD, 242/65, 242/67.1 [51] Int. Cl B65h 54/02, B65h 54/42 [58] Field of Search 242/18 DD, 18 R,

[56] References Cited UNITED STATES PATENTS 2,150,951 3/1939 Toole et al 242/18 DD Lingerfelt 242/18 DD Kieronski 242/18 DD FOREIGN PATENTS OR APPLICATIONS 675,487 12/1963 Canada 242/18 DD 770,474 7/1934 France 242/18 DD 817,763 8/1959 Great Britain 242/18 DD 1,138,335 1/1969 Great Britain 242/18 DD Primary Examiner-Stanley N. Gilreath Att0rneyRichard C. Sughrue et a1 [57] ABSTRACT 1 Claim, 3 Drawing Figures PAIENIEI) DEC 1 I I973 FIGI THREAD WINDING DEVICE The present invention relates to an apparatus for winding continuous thread onto a reel which rotates through being driven by contact with a friction roller.

Various types of apparatus in which a reel is driven by contact with a roller which rotates at constant speed are known in the prior art.

Where some of these apparatus are concerned, the reel rotates in a fixed position while, as the winding progresses, the roller is displaced, being for example mounted on an oscillating arm or on a carriage.

In other apparatus of simpler construction the friction roller rotates in a fixed position while the reel is mounted on a carriage or on an arm adapted to rotate about an axis in such a way that the reel is moved away from the roller as the winding increases.

Whichever solution is adopted, it is necessary for the pressure between roller and reel to be maintained within appropriate values during the winding.

If it is not, then serious lack of uniformity may occur either in the form of the reel or in the tension of the thread, which may result in breakage and difficulties when the thread itself is subsequently used. If the moving element (roller or reel) is mounted on a carriage capable of translatory movement, the pressure between roller and reel may be maintained at a constant level very easily, just as it is relatively simple to vary the pressure according to a preestablished law during winding of the reel.

If the movable element can rotate about a fixed axis, the solution of the problem is rather more difficult.

Furthermore, there are valid reasons, particularly economic reasons, for preferring the use of a rotating arm to a displaceable carriage.

The present invention relates to those apparatus in which winding of the continuous thread is carried out by contact between a roller and a wheel, when one of these two elements is mounted on an arm rotating about its axis.

According to the present invention, the tension of the thread is maintained constant during winding by an arrangement adapted to regulate the contact force between the roller and the reel, such regulation taking place as a function of the diameter of the reel while it is being wound, the-formation of a desirably regular reel being at the same time achieved under constant conditions of operation.

Although such an arrangement for regulating the force of contact between roller and reel may be applied both to devices in which the roller is mounted on an arm rotating about its axis and to devices in which the reel is mounted on such an arm, the apparatus according to the present invention is described with particular reference to the second case since this is the one which is most commonly encountered in industry.

Thus, an apparatus of the present invention comprises:

a friction roller rotating at a constant speed in a fixed position;

a reel on which the thread is to be wound rotating by contact with the said'friction roller;

an arm carrying the reel at one end, the other end being pivoted so as to allow the reel to be moved away from the friction roller as the amount of thread wound on the reel increases;

a system for regulating the force of contact between the reel being formed and the friction roller.

According to the present invention, the said contact force may be regulated by an arrangement which consists in applying to the reel-holding arm a balancing force contrasting with that due to the weight of the reel being formed and the weight of the relative arm, the said force being maintained constant for the time involved and, during the winding, generating moments in respect of the fulcrum of the reel-holding arm, which are variable according to a pre-determined law.

Thus, in the apparatus according to the present invention, the moment generated by the thrust of the friction roller on the reel depends at all times both upon the moments generated by the weight of the reelholdinj arm and the reel being formed, and that generated by the balancing force which is applied.

Thus, the apparatus may be essentially described as that in which the force of contact between the roller and the reel is controlled by, over the time involved, varying the balancing force applied at the arm, the said force generating in respect of the fulcrum of the reelholding arm moments which are variable over the time according to the diameter of the reel being formed.

In practice, in the achievement of the objects of the present invention, the reel-carrying arm is connected to a counter-weight or spring by means of an extending element which is wound on a cam pivoted on the reelholding arm, and during the thread-winding operations, the said cam is caused to rotate to considerably greater amplitude compared with the corresponding angular displacement of the arm, this effect of amplification being obtained by the use of epicyclic gears.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is schematic view of one form of the thread winding device according to the present invention when the diameter of the reeled thread is relatively small.

FIG. 2 is a view similar to FIG. 1 with the diameter of the reeled thread being substantially larger.

FIG. 3 is a view similar to FIG. 1 showing a modified form of the thread winding device according to the present invention.

According to the present invention, during angular displacement of the arm 3, the cam 4 is required to complete about its own axis a rotation of much greater amplitude in respect of the rotation of the arm in order to compensate for the greatly variable imbalances which occur during winding of the reel.

According to the present invention, this result may be achieved by the use of epicyclic gears which, in their simplest version (FIG. 3), consist of a satellite wheel 7A coaxial with the cam 4 and connected rigidly therewith, and a fixed toothed segment 8A coaxial with the fulcrum of the reel-holding arm. The gearwheel mechanism may be replaced by an equivalent solution such as that indicated in FIG. 1, consisting of a smooth wheel 7 coaxial with the cam 4 on pivot 11 and connected by a non-extensible strip 9 to the segment 8 coaxial with the fulcrum of the reel-holding arm.

FIGS. 1 and 2 show the winding device in empty and full conditions, respectively, of the reel 2.

It will be seen that the reel-carrying arm 3 is pivoted at 10 on a fixed bed M and extends obliquely upwardly towards the driving roll 1 rotatable on a fixed axis la so that a contact force S arises between the roller 1 and reel 2 due to the moments of the arm weight P and reel weight P about the pivot 10. In ordinary terms, S is the force by which the reel abuts against the driving roller 1.

In mathematical terms, the force S lies on line a passing through the axes of the roller 1 and reel 2 and having a moment arm b with respect to the pivot 10. Indicating by c and d the moment arms of P and P with respect to 10, the following equilibrium equation can be written:

from which we can calculate S:

S P.c P'.d/b

On winding of a thread the effective diameter and weight of the reel 2 progressively increase; this means that P, c, d and b are variable, whereby the value of S varies during the winding progress, while it would be desirable to keep S constant in order to obtain a uniform winding. Moreover, S as expressed by formula (2) is excessive in practice. Its value may be reduced by suitably increasing b; this expedient, however, would involve an undesirable increase in the length (and, consequently, in the weight) of the arm 3. The only practicable manner is to include in equation (2) a negative corrective moment -Z:

S R P.d -Z/b K constant (3) the moment Z being variable in a manner such as to impart to S a desired value, constant throughout the winding process.

In applicants structure, the moment Z is a product of a constant force O (which is the weight of the counterweight 5) by a moment arm e. More particularly, the counterweight 5 is attached at one end of a tape 6, the other end of which is wound on a cam 4 and riveted to the latter at 6"; the moment arm e is the distance between the run 6' of the tape 6 and a linefconducted through the pivot in direction parallel to 6'. The cam 4 is fast with a pulley 7 rotatable on a pin 11 carried by the arm 3. The pulley 7 represents a planetary gear in an epicyclic gearing including a circular segment 8 fixed to the bed M concentrically to the pivot 10. A tape 9 has its ends wound about the pulley 7 and segment 8 and riveted thereto at 9', 9", respectively. In this manner the pulley 7 meshes with the segment 8, the latter representing a sun wheel in the epicyclic gearing.

In FIG. 3, the pulley is shown as a toothed gear 7A and the segment as a toothed segment 8A. When the arm 3 moves in direction F, the gear 7A rolls on the segment 8A in the direction of the arrow. The angular displacement of the wheel 7A about its pin 11 depends upon the ratio of the radii of the wheel and segment. Thus, as the arm 3 moves through an angle of, say, 18 the gear .7A turns through 120, as does the cam 4.

In FIG. 1, in which the reel 2 is quite empty, the moment arms c and d are at their maximum. Under these conditions, the instantaneous lift L of the cam (i.e., the distance between the tangency point of the run 6 with the cam and axis of the pin 11) is selected such that equation (3) is satisfied; this is because L is a variable portion of the moment arm e of the counterweight 5.

During winding, the moment arms 6 and d decrease because of the clockwise displacement of the arm 3. However, as the arm displaces clockwise, the pull applied by the counterweight 5 to the tape 6 causes the cam 4 to rotate clockwise. During this rotation, the second tape 9 winds on the pulley 7 while unwinding from the segment 8 and controls in this manner the angular displacement of the pulley 7 just as the angular displacement of gear 7A in FIG. 3 is controlled by the mesh of the gear with the toothed segment 8A. Thus, the angular displacement of the cam 4 is at any moment a multiple of the angular displacement of the arm 3 and this fact permits to design the profile of the cam according to the requirements. For example, supposing that the arm 3 has rotated on its pivot 10 through 1, a new tangency point of the run 6' on the cam is reached and, by suitably designing the cam profile, the instantaneous lift L corresponding to this new tangency point can be selected so that, with the ensuing variation of the moment arm e, the equation (3) is again satisfied. In FIG. 2, corresponding to the end period of the thread winding process, it will be seen that the moment arms 0 and d are reduced to their minimum value while at the same time the weight of the reel became P" P. This involves a new equilibrium condition, in which both the instantaneous lift L of the cam and, consequently, the moment arm e are substantially reduced as compared with FIG. 1, whereby equation (3) is still satisfied. It will seem that in FIG. 2 the arm 3 has rotated through an angle X of about 18, but at the same time the cam 4 has rotated through about This amplified relation of cam displacement to the arm displacement allows a successful design of the cam profile. The amplifying factor" is given by the following relation (known in the art of epicyclic gearing):

wherein R is the radius of the sung gear (segment 8) and r is the radius of the planet gear (pulley 7). It will be seen that when the two radii are equal, the amplifying factor is 2. When r is 1 (one) and R is 4, the amplifying factor is 5; this means that a rotation of arm 3 through 18 produces an 18 X 5 90 rotation of the cam 4.

It would be impossible to distribute an instantaneous lift difference such as L-L on a cam are as narrow as 18. With applicants proposed planetary system this lift difference may be safely and exactly distributed over an arc of 90 and even more, if desired, depending upon the choice of the amplification factor mentioned above.

By means of the apparatus according to the present invention, the ratio between rotation of the cam and rotation of the reel-holding arm depends upon the radii of the wheel 7 and the segment 8, and these values are selected in such a way as to satisfy the afore-defined conditions.

It will furthermore be clear to a man skilled in the art thatit is possible to select the profile of the cam so that the balancing force acting tangentially on the cam gives rise (in relation to the fulcrum of the reel-holding arm) to moments which are variable over a period of time according to a pre-established law as a function of the diameter of the reel during winding.

In this way, the force with which the reel is driven by the friction roller can be made to vary according to a desired pattern and preferably it is maintained constant during the winding.

It is also possible to provide a cam having a plurality of radially adjustable segments in order to facilitate those adjustments which are required under various conditions of working, such as for example when the apparatus has to be used for successive windings of threads of different specific weights.

Thus, by a simple and economically suitable arrangement it is possible to wind the thread onto the reel under perfectly regular and controlled conditions, avoiding the disadvantages which are encountered with the apparatuses of the prior art.

The apparatus of the present invention furthermore makes it possible to obtain regular reels even of large diameter, and in particular it is possible to obtain reels of a diameter up to 600 mm while still operating under reliable conditions. Finally, the apparatus is sufficiently flexible that it can be rapidly adapted to the varying conditions which arise in practical working.

We claim:

1. An apparatus for the winding of continuous thread comprising:

a friction roller rotatable at constant speed about a fixed axis;

a reel, upon which the thread is to be wound, rotatable by contact with said friction roller;

an arm carrying the reel at one end thereof, the other end of said arm being pivoted so as to allow the reel to be moved away from the friction roller gradually as the amount of thread wound onto the reel increases;

cam means rotatably mounted on said arm intermediate the end thereof;

flexible means disposed about and secured at one end to said cam means, counter balancing means secured to the other end of said flexible means for applying a counter balancing force to said pivoted arm in opposition to the weight of said arm and said reel; and

means for varying the counter balancing force to vary the contact force between said reel and said roller;

said means for varying the counter balancing force comprising a wheel coaxial with and connected to said cam means for rotayion therewith about the axis thereof, a stationary circular segment coaxial with the pivot axis of said arm and means connected between said wheel and said segment for rotating said wheel through an angular displacement of considerably greater amplitude than the corresponding angular displacement of the reel holding arm about the pivot axis thereof. 

1. An apparatus for the winding of continuous thread comprising: a friction roller rotatable at constant speed about a fixed axis; a reel, upon which the thread is to be wound, rotatable by contact with said friction roller; an arm carrying the reel at one end thereof, the other end of said arm being pivoted so as to allow the reel to be moved away from the friction roller gradually as the amount of thread wound onto the reel increases; cam means rotatably mounted on Said arm intermediate the end thereof; flexible means disposed about and secured at one end to said cam means, counter balancing means secured to the other end of said flexible means for applying a counter balancing force to said pivoted arm in opposition to the weight of said arm and said reel; and means for varying the counter balancing force to vary the contact force between said reel and said roller; said means for varying the counter balancing force comprising a wheel coaxial with and connected to said cam means for rotayion therewith about the axis thereof, a stationary circular segment coaxial with the pivot axis of said arm and means connected between said wheel and said segment for rotating said wheel through an angular displacement of considerably greater amplitude than the corresponding angular displacement of the reel holding arm about the pivot axis thereof. 